The Ministry of Defence is at the centre of a new crisis over the abuse of prisoners after it was disclosed yesterday that a number of British military interrogators may be charged as war criminals.

The development comes after videos submitted as evidence to a high court case appeared to show members of a military intelligence unit threatening, abusing and humiliating Iraqi detainees at a secret prison near Basra.

Three men have been referred to the director of service prosecutions (DSP) after an investigation – which is thought to have centred on the video films – considered whether they had breached the International Criminal Court Act.

The referral to the DSP was accompanied by "a recommendation that he consider charges under the 2001 act", Philip Havers QC, counsel for the MoD told the high court yesterday. He said that article 8 of the act prohibits a number of actions as war crimes, including "committing outrages upon personal dignity, in particular humiliating and degrading treatment".

In the original case, the high court was being asked by lawyers representing 222 Iraqi men detained by British forces to order a public inquiry to examine their allegations of systematic and brutal mistreatment.

As well as the three men who have been referred to the DSP, a number of other military interrogators – some of them reservists with the Territorial Army or the Royal Navy and RAF reserves – are also under investigation. There is the possibility that they too could face war crimes charges.

Any prosecutions would be almost unprecedented. In 2006, one British soldier pleaded guilty to a war crime charge arising out of his mistreatment of Baha Mousa, the Iraqi hotel receptionist who was tortured to death by British troops in Basra three years earlier. He was jailed for a year and expelled from the army. Six of his comrades were cleared of a number of serious charges. No other member of the British armed forces has ever been convicted of a war crime.

Faced with the possibility of more servicemen being accused of war crimes, MoD officials have been increasingly concerned in recent days about the damaging effect such charges would have upon the morale and reputation of the services.

The MoD has been unable to explainwhy the films were made, or why training material used to instruct would-be interrogators in techniques that appear to breach the Geneva conventions was not disclosed to the court.

The investigation into alleged war crimes is being undertaken by a military police team known as the Iraq historical allegations team (IHAT).

An MoD spokesman said: "We have acknowledged that if these allegations do prove to be true then they could be prosecuted as war crimes under the international criminal court. That is why we have set up IHAT, to investigate allegations thoroughly."

While acknowledging that members of the armed forces could face war crimes trials, the MoD stressed tonight that the allegations remain unproven. "If untrue, making such serious allegations falsely would be a heinous slur on members of the army," the spokesman said. Nevertheless, the IHAT investigators have clearly concluded there may be sufficient evidence to justify war crimes charges. The 1,253 video and audio recordings that interrogators made themselves are thought to be central to the military police investigation.

Last month the Guardian reported that trainee interrogators have been told that they should employ techniques that include threats, sensory deprivation and enforced nakedness in an apparent breach of the Geneva conventions. Training materials drawn up secretly in recent years tell interrogators they should aim to provoke humiliation, insecurity, disorientation, exhaustion, anxiety and fear in the prisoners they are questioning, and suggest ways in which this can be achieved.